This invention deals with a valve used for controlling bulk dispensing of viscous substances such as sauces, salad dressings, catsup, mustard or various other substances, especially where it is desirable to have a valve that can be operated with one hand while the other hand, for example, is holding the receiving vessel, such as in fast-food restaurants, etc. These substances are commonly packaged in flexible bags or pouches which may or may not be contained in boxes. The prior art provides two main types of valves for this purpose. One is the rotatable cylindrical tube type which cannot be disassembled for cleaning, and this allows for residue accumulation, and cannot be tilted in dispensing so that all the contents of the bag is discharged. The other is the ball-type which also cannot be disassembled for cleaning and allows for residue accumulation.